Sticky VTEC and poor cold running

[Crazylegs]

Hey all,

I've mentioned before I've had an issue with a slightly sticky VTEC and also running from stone cold the car is hesitant, it goes into an almost limp mode of sorts for a minute or so as if it's not getting enough fuel in and then it's fine.

I thought when Chris mapped it it may have eradicated these issues and it hasn't, and the change of exhaust to the RM01A also hasn't cleared it. A fellow forum member has suggested getting a new VTEC solenoid gasket, will this be suffice and could this potentially be the issue?

Any idea why the Honda settings would be causing the car to run poor from cold? Also why it's hesitant instead of being a smooth crossover into VTEC?

I'm keen to fix these issues before it goes in for a map tweak at the beginning of September.

For people's information the car didn't throw up any error codes when Chris was mapping the car.

 

[Jvzr]

Is it when cutting into VTEC it hesitate?
Once it settles in VTEC is it ok?

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[Jvzr]

What airfilter?

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[Crazylegs]

Hey dude

Tegiwa intake.

Bascially as it engages VTEC it's ever so slightly hesitant, as though it's sticking slightly and then engages.

Power delivery is all good otherwise, once into VTEC it pulls very strong it's just a second of so of hesitancy in all gears.

 

[DC5Curn]

Wouldnt you need a new Solenoid as changing the gasket wouldnt make a difference would it?

Dont they have a filter that can get clogged aswell?

 

[Crazylegs]

Think you could be right there, I think the filter does get clogged too as oil goes through it.

Do you think that could be causing the sticky VTEC? It's not as though it doesn't engage VTEC which is weird, just sticks then engages.

 

[SamDC5]

Something definitely sounds off, the only reason I can think it would run poorly when cold is IACV.

It is known the solenoids can become 'sticky'. It's well worth taking the VTEC solenoid off and replacing the gauze. It's fairly easy to access and its held on with a few bolts.

It's hard to give advice without seeing the car and how it reacts but based on the information you've given those are the things I would investigate.

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[ollieh17]

I was right about the exhaust then lol... did you ever do a compression test?

 

[Crazylegs]

I thought the same, IACV but from what I‘ve read this affects the revs and cause it to rev hunt when warm, mine is fine when warm so I‘m not sure whether it is the IACV. It‘s no major issue just a tad annoying but I can live with it. More keen to sort the hesitant VTEC out.

I will try purchasing a new gauze for the Solenoid and see if it helps.

 

[Crazylegs]

I was right about the exhaust then lol... did you ever do a compression test?

Ha ha you're not right yet lol, I haven't had it remapped yet so I will come back with the results.

Not had it compression tested as it was booked in for its MOT and a load of other things so I didn't get the compression done as the guys doing the work were rammed.

 

[Mebz]

Is the vtec hesitant on light throttle and/or full throttle?

 

[Crazylegs]

Is the vtec hesitant on light throttle and/or full throttle?

Full throttle, about the only time I'm in vtec lol.

 

[mikegsi]

Hey all,

I've mentioned before I've had an issue with a slightly sticky VTEC and also running from stone cold the car is hesitant, it goes into an almost limp mode of sorts for a minute or so as if it's not getting enough fuel in and then it's fine.

I thought when Chris mapped it it may have eradicated these issues and it hasn't, and the change of exhaust to the RM01A also hasn't cleared it. A fellow forum member has suggested getting a new VTEC solenoid gasket, will this be suffice and could this potentially be the issue?

Any idea why the Honda settings would be causing the car to run poor from cold? Also why it's hesitant instead of being a smooth crossover into VTEC?

I'm keen to fix these issues before it goes in for a map tweak at the beginning of September.

For people's information the car didn't throw up any error codes when Chris was mapping the car.

Hey, old post revival but I’m trying to solve some cold start issues too.

when starting from cold my car runs very lumpy with the revs bouncing and ‘hunting’ but rough sounding . If I leave it I get the P2647 code which relates to the VTEC Solenoid. If I blip the the throttle a second after starting it seems to sort the idle and the car runs perfect. It only happens when the car is cold and hasn’t been started for some time.

I replaced the filter but that had no effect. I’ve deleted the IACV but had similar issues before I deleted it.

Not sure whether to replace the VTEC Solenoid as it’s quite an expense to sort out a cold start rough idle?

My setup is a K24a3/K20z4 Frank build in a FN2.